Friday, April 29, 2016

Automatic rotary dials using various exchange prefixes per finger hole via exchanges around the tri-state area was the reason that Keystone Telephone in the Philadelphia area was the preferred business to business telephone over that of the operators at AT&T that connected calls in the early days of the twentieth century and the reason many Philly businesses had two phone companies up until 1945 when AT&T bought out Keystone.